Anaerobic Bact. infxns

Question 1

What do strict anaerobes lack that make oxygen toxic?

Answer 1

catalase and SOD

(degrades H2O2 and O2- respectively)

• but!! Anaerobes associated with disease are somewhat aerotolerant, and may produce some catalase and/or SOD
• virulent

Question 2

2 Hallmarks of anaerobic GNR and cocci

Answer 2

1. Abscess formation

2. Mixed (polymicrobial) infxn w/ anaerobes + facultative or aerobic organisms

Question 3

Formation of anaerobic abscess:

acute vs chronic stage

Answer 3

Acute stage:
Aerobes and facultative org. predominate
- febrile, hypotensive

Chronic:
Anaerobes predominate
- Formation of fibrin-encased abscess

Question 4

Virulence of bacteroides fragilis

Answer 4

Isolated from 80% of abdominal abscesses

1. Aerotolerant
   - prod Catalase and SOD
2. Extracellular enzymes (phospholipase, collagenase)
3. Capsule
   - abscess formation

Question 5

Passive immunization of tetanus

Answer 5

Passive: Administration of Immunoglobulin

- High titer anti tetanus immunoglobulin
- Does not reverse what has been done

*pt will not get immediately better

Question 6

Vaccination against tetanus

Answer 6

Tetanus toxoid

Question 7

Which form of botulism involves ingestion of preformed toxin?

Answer 7

C. botulinum
- food born

*infant and wound botulism is due to ingestion of spores in honey

Question 8

tx for botulinum

Answer 8

antitoxin

- equine, seven valent